Lubricating oil composition containing oxyalkylated carbonated basic sulfonate



United States atent 3 032 501 LUBRICATING OIL CbMiOSITION CONTAINING OXYALKYLATED CARBONATED BASIC SUL- FONATE Richard L. Ferm, El Cerrito, Califi, assignor to California Research Corporation, San Francisco, Calif., a corporation of Delaware No Drawing. Filed Dec. 29, 1958, Ser. No. 783,118

5 Claims. (Cl. 252-33) This invention is directed to improved metal salts of sulfonic acids particularly useful as lubricating oil additives; more particularly, to lubricating oil compositions having incorporated therein certain modified metal sulfonates.

Crank case lubricants in internal combustion engines are exposed to extremely severe conditions of operation, particularly in diesel engine service, wherein the lubricating oil compositions encounter temperatures as high as 650 F. and higher, and pressures of 1,000 psi. and higher. Under such conditions of operation, the lubricating oil compositions have a tendency to deteriorate, forming gummy deposits on the piston rings, the piston lands, and the skirts of the pistons.

Because of their detergent characteristics, metal sulfonates have been particularly effective as additives for heavy duty oils used for lubricating high speed diesel and gasoline engines. More recently, the so-called basic metal sulfonates, that is, metal salts of sulfonic acids having an excess of base metal present over that necessary for the formation of a neutral sulfonate, have become of greater importance for use as additives in lubricating oil compositions requiring acid neutralizing agents. Thus, basic metal sulfonates are useful not only as detergents, but also as acid neutralizers in lubficating oil compositions. However, the use of basic metal sulfonates results in the formation of heavy top ring groove deposits in diesel engines. Such deposits cause ring sticking, markedly reducing the effectiveness of the top rings to seal off the products of the combustion chamber from the crank case, etc. Thus, combustion products move past the piston rings into the crankcase oil, resulting in damage to the pistons and cylinder walls, and a dilution and acidification of the lubricating oil. Furthermore, ring sticking caused by such deposits results in high wear, ring breakage, general mechanical failures, etc. i

The particular basic sulfonates described hereinbelow are useful in multi-graded, and heavy duty oils for gasoline engines and diesel engines. Multi-graded oils have various polymeric agents therein to improve, the viscosity index of the multi-graded oils. However, some of the viscosity index improving agents result in the formation of heavy piston groove deposits during the operation of the engines. Such deposits result in sticky piston rings, causing gases to escape into the crankcase, thus causing excess acid formation and dilution of the lubricating oil.

It is, therefore, an object of this invention to set forth a lubricating oil composition useful for heavy duty diesel engine service; inhibiting the formation of heavy top groove deposits.

In accordance with this invention, it has been discovered that lubricating oil compositions useful for heavy duty service in diesel engines are obtained by incorporating in base oils oxyalkylated-carbonated basic polyvalent metal sulfonates in minor amounts sufficient to inhibit top groove deposit formation. Thus, the lubricating oil compositions of this invention comprise an oil of lubricating viscosity in combination with an oxyalkylated-carbonated basic polyvalent metal sulfonate.

As used herein, the term basic metal sulfonates means a metal salt of a sulfonic acid having an amount of metal at least 100 mol percent in excess of that suflicient for the formation of a neutral metal sulfonate,

ice

The oxyalkylated-carbonated basic metal sulfonates herein are particularly effective as detergents in multigraded oils wherein the acrylate and methacrylate type polymers are used therein as viscosity index improving agents.

The oxyalkylated-carbonated basic metal sulfonates described herein are derived from polyvalent metal sulfonates which may be represented by the formulas and[(R) ASO M wherein R is a high molecular weight cyclic, straight-chained or branch-chained saturated or unsaturated essentially hydrocarbon radical having a molecular weight ranging from about to about 800; A is an aromatic radical, such as benzene, naphthalene, anthracene, biphenyl, etc.; a is a number having a value of 1 to 4; M is a polyvalent metal, and x is a number having a Value equal to the valence of the polyvalent metal M. As the metal, barium is preferred. However, although not as effective, other suitable metals include other alkaline earth metals (i.e., calcium and strontium), and magnesium.

Examples of suitable hydrocarbon radicals are the following: dodecane, hexadecane, eicosane, triacontane radicals; radicals derived from petroleum hydrocarbons, such as white oil, wax, olefin polymers (e.g., polypropylene and polybutylene, etc.). The sulfonic acids used in preparing the oil soluble metal sulfonates of this invention also include the oil soluble sulfonic acids derived from petroleum, such as the mahogany acids, and the synthetic sulfonic acids prepared by various methods of synthesis (e.g., sulfonic acids prepared by reacting a chlorinated white oil with benzene, using hydrofluoric acid as a catalyst, then treating the resulting white oil alkylated benzene with chlorosulfonic acid or fuming sulfuric acid to form a white oil benzene sulfonic acid).

The metal sulfonates which are used in the formation of the basic sulfonates subsequently used in the formation of carbonated oxyalkylated basic metal sulfonates of this invention are exemplified as follows: calcium white oil benzene sulfonate, magnesium white oil benzene sulfonate, barium white oil benzene sulfonate, calcium dipolypropene sulfonate, magnesium dipolypropene benzene sulfonate, barium dipolypropene benzene sulfonate, barium mahogany petroleum sulfonate, calcium mahogany petroleum sulfonate, calcium triacontyl sulfonate, barium triacontyl sulfonate, magnesium triacontyl sulfonate, calcium lauryl sulfonate, barium lauryl sulfonate, magnesium lauryl sulfonate, etc.

Although not intended to be bound thereby, the following equations under I and II hereunder illustrate schematically the formation of oxyalkylated, carbonated, polyvalent metal basic sulfonates of this invention.

wherein R and R'are hydrocarbon substituents on thebenzene ring, a is a number having a value from 1 to 4, b is a number having a value from 1 to 3, Q represents 001120112011 001120112011 Ba or Ba OCHzCHzOH H 7 or'mixtures thereof, and L represents wherein R is the same as identified hereinabove.

The R and R in the above formulas represent hydrocarbon radicals containing from 16 to 70 carbon atoms, more particularly aliphatic radicals containing from 18 to 40 carbon atoms. In addition to the barium as exemplified in the above formulas, the metals include the alkaline earth metals such as calcium, strontium and magnesium. vIn addition to the ethylene oxide, there may be used other alkylene oxides wherein the oxygen atom is attached to two adjacent carbon atoms forming an oxirane ring. Such alkylene oxides are exemplified by propylene oxide-1,2; butylene oxide-1,2; butylene oxide- 2,3; amylene oxide-1,2; amylene oxide 2,3; the octylene oxides, etc. The alkylene oxides may also be used as mixtures thereof; for example, mixtures of ethylene oxide and propylene oxide.

The specific mol ratios of the various reactants used in the formation of the carbonated, oxyalkylated basic sulfonates of this invention are set forth hereinbelow as follows:

In the preparation of the basic sulfonates, the amount of basic hydroxide (or oxide) is at least 1 mol to as high as 10 mols in excess of that necessary for the formation of a neutral metal salt of a sulfonic acid. It is preferred that the basic sulfonate contain from 1 to 3 mols metal in excess of that necessary for the formation of a neutral sulfonate. With regard to the alkylene oxide, it is critical to use from 0.1 to 1 mol of alkylene oxide per equivalent of basic metal content; from 0.5 to 1 mol per equivalent of basic metal content being preferred.

With regard to the carbon dioxide, it is essential to use at least 0.1 mol of carbon dioxide per equivalent of basic metal content, with a preferred range of 0.25 mol to 1 mol of carbon dioxide per equivalent of basic metal content.

In the formation of lubricating oil compositions containing the oxyalkylated carbonated basic sulfonates of this invention, the lubricating oil compositions contain this new additive in amounts suflicient to inhibit piston groove deposit formation; which amounts may be from 0.5%, by weight, to 10%, by weight; with 3%, by weight, to 7%, by weight, being preferred.

The following examples illustrate the formation of oxyalkylated carbonated basic metal sulfonates in accordance with this invention.

EXAMPLE I.OXYALKYLATED CARBONATED BASIC BA RIUM SULFONATE 1500 grams of basic barium petroleum sulfonate was charged to a reaction vessel through which was blown nitrogen at 300 C. Ethylene oxide gas was bubbled into the basic sulfonate at 300 F. until 33.5 grams of ethylene oxide had been absorbed. The product obtained thereby was then blown with CO gas at 300 F. for one hour. The resulting product had absorbed 2.22%, by weight, of ethylene oxide and 1.60%, by weight, of carbon dioxide.

The basic barium petroleum sulfonate was a lubricating oil concentrate containing a total of 12.48% barium, 7.12% of which was basic barium, and 4.8% of which was barium from the neutral barium sulfonate. The petroleum fraction of the basic sulfonate was derived from a California solvent refined naphthenic base oil having a viscosity of 480 SSU at F.

EXAMPLE II.OXYALKYLATED CARBONATED BASIC CALCIUM SULFONATE 1200 grams of a basic calcium petroleum sulfonate was charged to a reaction vessel. The sulfonate solution was heated to 320 F., followed by bubbling in of 30.0 grams of ethylene oxide over a period of 6 hours at 320 F. The resulting product was then blown with CO gas at 300 F. for a period of 1 hour. The product absorbed 2.5%, by weight, of ethylene oxide.

The basic calcium petroleum sulfonate was a lubricating oil concentrate of the sulfonate; the concentrate containing a total of 4.5% calcium, wherein ,thebase ratio (i.e., the mol ratio of basic calcium to neutral sulfonate calcium) was 3 to 1. The petroleum fraction was derived from a California parafiinic baselubricating oil having a viscosityof 480 SSU at 100 F.

EXAMPLE III.--CARBONATED BASIC BARIUM SULFONATE 50 lbs. of a lubricating oil concentrate of a basic bariumpetroleum sulfonate (1) was charged to a. 15 gallon stainless steel reactor and heated to 300 F. Carbon dioxide gas was bubbled through the sulfonate for a period of 5 hours at 300 F. The resulting product was a bright amber colored liquid containing 12.1% of total barium (4.75% of which is present as a barium sulfonate; and 7.20% of which was present as basic barium).

The ratio of barium present as carbonated base to that present as sulfonate was 1.52.

(1) The oil concentrate of the basic barium sulfonate contained 12.48%, by weight, barium, of which 7.12% was basic barium and 4.8% was from the neutral barium sulfonate. The organic radical of the sulfonate was derived from a California solvent refined naphthenic base oil having a viscosity of 400 SSU at 100 F.

Lubricating oil compositions containing oxyalkylated carbonated basic metal sulfonates of this invention were tested in engines as described hereinbelow and the data obtained are set forth in Table I.

The amounts of additives used in the lubricating oil compositions, unless specified as percent by weight, are set forth as millimols per kilogram of finished oil composition (mM./kg.). The millimol content is based on the metal of the additive.

Test oils (1), (2) and (4) consisted of a base oil, which was a California solvent refined paraffinic base oil having a viscosity of 150 SSU at 100 F.; 60 mM./kg. of the identified oxyalkylated-carbonated basic sulfonate; 12 mM./kg. of a zinc butyl, hexyl dithiophosphate; and 6.0% by weight, of Acryloid 966, which is a viscosity improving agent used in the preparation of multi-graded oils and identified as a mixed C -C alkyl methacrylate copolymerized with a nitrogen-containing polar compound, and sold by Rohm and Haas Company.

Test oil (3) consisted of the same base oils as described for tests (1), (2) and (4), plus 18 mM./kg. of a zinc butyl, hexyl dithiophosphate and 8%, by weight, of Acryloid 966.

Test oil (5) was of the same composition as test oil (1) with the exception that the base oil was a Midwestern paratfinic base oil having a viscosity of 202 SSU at 100 F.

The tests were carried out in a full scale engine described as follows:

(a) The engine used for the L-l test was a caterpillar single cylinder, 5 /4" bore diesel engine; it was run for 120 hours at 1,000 r.p.m. at a load of 19.8 brake horse power, or a temperature of 145 F. to 150 F., jacket temperature of 175 F. to 180 F., using a fuel containing 1% sulfur. The tests were made under Supplemental I conditions. The value numbers refer to the percent of total area of groove filled with deposit, and percent of area of land containing deposits.

(480 Hour Test.)

Lubricating oils which are suitable as base oils for the grease compositions of this invention include a wide variety of oils, such as naphthenic base, parafiin base, and mixed base oils; lubricating oils derived from coal products and synthetic oils, e.g., alkylene polymers (such as polymers of propylene, butylene, etc., and mixtures thereof), alkylene oxide type polymers, dicarboxylic acid esters, liquid esters of acids or" phosphorus, aromatic type base oils, polymers of silicon. etc.

Synthetic oils of the alkylene oxide type polymers which may be used include those exemplified by the alkylene oxide polymers (e.g., propylene oxide polymers) and derivatives, including alkylene oxide polymers prepared by polymerizing the alkylene oxides, e.g., propylene oxide, in the presence of water or alcohol, e.g., ethyl alcohol, esters of ethylene oxide type polymers, e.g., acetylated ethylene oxide polymers prepared by acetylating ethylene oxide polymers containing hydroxyl groups; polyethers prepared from ethylene glycols, e.g., ethylene glycol, etc.

The polymeric products prepared from the various alkylene oxides and alkylene glycols may be polyoxyalkylone diols or polyalkylene glycol derivatives; that is, the terminal hydroxyl groups may remain as such or one or both of the terminal hydroxyl groups can be removed during the polymerization reaction by esterification or etherification.

Synthetic oils of the dicarboxylic acid ester type include those which are prepared by esterifying such dicarboxylic acids as adipic acids, azelaic acid, suberic acid, sebacic acid, alkanol succinic acid, etc., with alcohols such as butyl alcohol, hexyl alcohol, Z-ethylhexyl alcohol, dodecyl alcohol, etc.

Synthetic oils of the aromatic type include those which are prepared by alkylating benzene (e.g., monoalkyl benzene such as dodecyl benzene, tetradecyl benzene, etc., and dialkyl benzenes (e.g., n-nonyl 2-ethylhexyl benzene); aryl esters (e.g., bis(carbethoxydecyl) benzene, 2-ethylhexyl phenyl decanoate, bis(carbethylhexoxydecyl) benzene, etc.). Other aryl type synthetic oils include indane and derivatives thereof (e.g., 1,1,3-trimethy1-3- phenyl indane; 1,1,3-trimethyl-3-n-nonyl phenyl indane, etc.); bis(phenoxyphenyl) alkanes (e.g., bis(phenoxyphenyl) nonane, etc.); polyaryl alkanes (e.g., bis(diphenyl) nonane, phenyl (n-nonylphenyl) isodecane (diphenyl decane, etc.); polyalkyl terephenyls; alkyl diphenyl ethers, etc.

Synthetic oils of the type of polymers of silicon include the esters of silicon and the disiloxanes which include those exemplified by tetraethyl silicate, tetraisopropyl silicates, tetra(4-methyl-2-ethyl) silicate, hexyl(4- methyl-2-pentoxy) disiloxane, poly (methyl) siloxane, poly(methyl phenyl) siloxanes, etc.

The above base oils may be used individually or in combinations thereof, wherever miscible or wherever made so by the use of mutual solvents.

In addition to the components set forth hereinabove, the lubricating oils of this invention may contain oxidation inhibitors, corrosion inhibitors, thickening agents, viscosity index improving agents, pour point depressants, other detergents, etc.

I claim:

1. A lubricating oil composition comprising a major proportion of an oil of lubricating viscosity, and from about 0.5% to about 10%, by weight, of an oxyalkylatedcarbonated basic alkaline earth metal sulfonate obtained by (1) reacting a basic alkaline earth metal sulfonate containing from 1 to 3 mols of metal in excess of that of a neutral metal sulfonate of the formula wherein R is an alkyl radical containing from 18 to 40 carbon atoms, A is a phenyl radical, a is a number having a value from 1 to 4, and M is an alkaline earth metal; with from 0.5 to 1 mol of alkylene oxide per equivalent of said excess metal of (1); and (2) reacting the oxyalkylated basic alkaline earth metal sulfonate of (1) with 0.25 to 1 mol of CO per equivalent of said excess basic metal of (1).

2. The lubricating oil composition of claim 1 wherein said alkaline earth metal is barium.

3. The lubricating oil composition of claim 1 wherein said alkaline earth metal is calcium.

4. The lubricating oil composition of claim 1 wherein said alkylene oxide is ethylene oxide.

5. A lubricating oil composition comprising a major proportion of an oil of lubricating viscosity, and from about 3% to about 7%, by weight, of an oxyalkylatedcarbonated basic alkaline earth metal sulfonate obtained by (1) reacting a basic alkaline earth metal sulfonate containing from 1, to 3 mols of metal in excess of that of a neutral metal sulfonate of the formula [(R) ASO M wherein R is-analkyl radical containing from 18 to 40 0.25 to 1 mol of CO per equivalent of said excess basic metal of (1).

References Cited in, the file of this patent UNITED STATES PATENTS 2,676,925 Linstrom et a1 Apr. 27, 1954 2,856,361 Schlicht Oct. 14, 1958 2,878,185 Weamer Mar. 17, 1959 TATES PATENT OFFICE OF CORRECTION May 1 1962 UNITED 5 CERTIFICATE Patent No. 3,032,501

Richard L. Ferm peers in th d Letters Paten e above numbered patrtified that error ap t should read as It is hereby ce ent reqliring correction and that the sai corrected below.

300 C. read 300 F.

Column 4 line 40. for

Signed and sealed this 4th day of September 1962.

(SEAL) IXttest:

DAVID L. LADD ERNEST W. SWlDEF Commission r of Patents Attesting Officer 

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF AN OIL OF LUBRICATING VISCOSITY, AND FROM ABOUT 0.5% TO ABOUT 10%, BY WEIGHT, OF AN OXYALKYLATEDCARBONATED BASIC ALKALINE EARTH METAL SULFONATE OBTAINED BY (1) REACTING A BASIC ALKALINE EARTH METAL SULFONATE CONTAINING FROM 1 TO 3 MOLS OF METAL IN EXCESS OF THAT OF A NEUTRAL METAL SULFONATE OF THE FORMULA 